Such portable lighting devices may be configured as electric torches, flashlights, hand lamps, or also cap lamps. One or more batteries serve power supply. These batteries may be of a rechargeable type.
If a corresponding electrical contact is established between light source and voltage supply, the light source is switched on. The light source shows a specific luminous intensity distribution that can be varied by a light distribution device, if necessary.
So far LED light sources, halogen envelope lamps or also incandescent lamps have been known in practice as light sources whose luminous intensity distribution can be varied by adjusting a parabolic or hyperbolic reflector. Said reflector may be arranged at a side of the light source opposite the light exit direction.